Quarterly report [Sections 13 or 15(d)]

Basis of Presentation - Additional Information (Details)

Basis of Presentation - Additional Information (Details)									3 Months Ended		6 Months Ended		12 Months Ended	48 Months Ended
	Apr. 28, 2025 USD ($) $ / shares shares	Feb. 19, 2025 USD ($)	Jan. 31, 2025 USD ($) shares	Dec. 10, 2024 USD ($)	Aug. 09, 2024 USD ($) $ / shares shares	Oct. 07, 2022 USD ($) $ / shares	Sep. 08, 2020 USD ($) Debtinstrument	Jan. 21, 2020 USD ($) Debtinstrument	Jun. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) $ / shares shares	Jan. 31, 2025 USD ($) shares	Aug. 04, 2025 shares	May 03, 2023 $ / shares	Oct. 17, 2022 USD ($)	Feb. 10, 2021 $ / shares	Feb. 08, 2021 $ / shares	Oct. 31, 2020 $ / shares	Oct. 27, 2020 $ / shares
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Net losses									$ 6,509,000	$ 4,997,000	$ 11,400,000	$ 12,098,000	$ 24,774,000
Accumulated deficit									$ 497,472,000		$ 497,472,000		$ 486,072,000
Aggregate principal amount of exchangeable notes														$ 40,691,000
Ordinary shares, shares issued \| shares	3,040,000								42,131,328		42,131,328		31,534,233
Price per ordinary share \| $ / shares	$ 0.9
Prefunded warrants to purchase shares of common stock \| shares	2,515,556
Prefunded warrant issued per share \| $ / shares	$ 0.89
Aggregate gross proceeds from ordinary shares	$ 5,000,000
Net proceeds from issuance of common stock	$ 4,177,000
Accrued and unpaid interest														3,071,000
Cash and cash equivalents									$ 13,026,000		$ 13,026,000		$ 24,125,000
Ordinary shares, par value \| $ / shares									$ 0.01		$ 0.01		$ 0.01			$ 0.01
Warrants to purchase ordinary share, exercise price \| $ / shares	$ 0.01
Authorized amount for sale of stock		$ 150,000,000
Maximum
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Value of shares and securities may offer and sell																	$ 100,000,000
Subsequent Events
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Ordinary shares, shares issued \| shares															2,525,578
Sales Agreement With H.C. Wainwright
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Ordinary shares, par value \| $ / shares						$ 0.01
Sales Agreement With H.C. Wainwright \| Maximum
Organization Consolidation And Presentation Of Financial Statements [Line Items]
May offer and sell ordinary shares for additional aggregate offering price				$ 25,000,000
May offer and sell ordinary shares for aggregate gross sales proceeds						$ 16,000,000
2024 Rights Offering
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of units sold \| shares					6,121,965
Subscription price per whole unit \| $ / shares					$ 1.21
Warrants to purchase ordinary share, exercise price \| $ / shares					$ 1.21
Aggregate net proceeds from rights offering					$ 5,430,000
2024 Rights Offering \| 1-Year Warrant
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of shares that can be purchased with each warrant \| shares					0.5
Warrants to purchase ordinary share, exercise price \| $ / shares									1.21		1.21
2024 Rights Offering \| 5-Year Warrants
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Warrants to purchase ordinary share, exercise price \| $ / shares					$ 1.21				$ 1.21		$ 1.21
October Offering
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Warrants to purchase ordinary share, exercise price \| $ / shares																				$ 12.1875	$ 9.75
February Underwritten Offering
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Warrants to purchase ordinary share, exercise price \| $ / shares																		$ 21.5625	$ 21.5625
2025 Exchangeable Notes \| Private Placement and Rights Offering
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Aggregate principal amount							$ 51,808,000
Debt instrument interest rate								6.50%
2025 Exchangeable Notes \| Private Placement
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Aggregate principal amount								$ 51,588,000
Debt instrument price per unit								1,000
RLNs \| Private Placement and Rights Offering
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Aggregate principal amount							$ 500	104,000
RLNs \| Private Placement
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Aggregate principal amount								$ 103,000
Number of debt instruments within each notes \| Debtinstrument							50	50
Exchangeable Notes
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Aggregate principal amount of exchangeable notes			$ 11,117,000											$ 40,691,000
Ordinary shares, shares issued \| shares			3,760,155						3,760,155		3,760,155			3,760,155
Accrued and unpaid interest														$ 3,071,000
Accrued interest balance amount			$ 3,628,000
Repayment of aggregate principal amount			$ 11,117,000
Exchangeable Notes \| Private Placement
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Aggregate principal amount of exchangeable notes														$ 40,691,000